Peep sights?

[varsity07840]

A Williams receiver sight with a concave bottom works very well mounted just ahead of the receiver. I glued it with Loctite 380 Black Max. A good wack with a light hammer will knock it off after a little heat and the residue can be cleaned off with acetone or lacquer thinner.

[Billy-Mac]

I use this Lyman Products EyePal Bow/Handgun Pack. It's a peep sight that just sticks on your shooting glasses. It's cheap, no modification needed to your gun and works great for my 65-year-old eyes.